Technologies for Autonegotiating 10G and 1G Serial Communications Over Copper Cable

ABSTRACT

Technologies for autonegotiation of communications operational modes over copper cable include a network port logic having a communication link coupled to a remote link partner. The network port logic may start an autonegotiation protocol upon reset, when the link is broken, or upon manual renegotiation. The network port logic transmits an autonegotiation page to the remote link partner that indicates single-lane communications ability over copper cable. The network port logic receives an autonegotiation page from the link partner indicating single-lane communications ability over copper cable. If the network port logic and link partner have a common single-lane communication ability, the link may be activated. The autonegotiation pages may be base pages or next pages. The single-lane communication ability may be indicated by one or more bits of the autonegotation pages. The link may be established at 1 gigabit or 10 gigabits per second. Other embodiments are described and claimed.

BACKGROUND

Ethernet using copper cabling and backplane may use several differentoperational modes for communication links. The various operational modesmay have different link speed, line encoding, and other characteristics.Certain Ethernet standards define methods to autonegotiate one ofseveral specifically enumerated physical layer technologies andoperational modes to be used for a particular communication link. Onesuch autonegotiation protocol is defined in Clause 73 of the IEEEstandard 802.3 (2012). For copper cable applications, the lowest-speedoperational mode available for clause 73 autonegotiation is 40-gigabitcommunication over four physical lanes (40 GBASE-CR4). Additionally,clause 73 always attempts to activate the fastest common communicationtechnology between the link partners.

Lower link speeds may be desirable for certain applications, such as forlow-power applications including wake-on-LAN (WOL) applications, or foruse with broken or lower-quality media (i.e., cable). For example, lowercommunication speed may be desirable when one of several physical lanestypically used is broken or otherwise not operable. Lower link speedsmay be manually reconfigured using firmware or software solutionsexecuted by both of the link partners. Successful manual reconfigurationof link technology may require close synchronization of changes made toboth link partners.

BRIEF DESCRIPTION OF THE DRAWINGS

The concepts described herein are illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. Where considered appropriate, referencelabels have been repeated among the figures to indicate corresponding oranalogous elements.

FIG. 1 is a simplified block diagram of at least one embodiment ofEthernet port logic for link technology autonegotiation ;

FIG. 2 is a simplified block diagram of at least one embodiment of acomputing device that may include the Ethernet port logic of FIG. 1;

FIG. 3 is a simplified flow diagram of at least one embodiment of amethod for link technology autonegotiation that may be executed by theEthernet port logic of FIGS. 1 and 2; and

FIG. 4 is a schematic diagram of embodiments of autonegotiation pagesthat may be used by the Ethernet port logic of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the drawings and will be describedherein in detail. It should be understood, however, that there is nointent to limit the concepts of the present disclosure to the particularforms disclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives consistent with the presentdisclosure and the appended claims.

References in the specification to “one embodiment,” “an embodiment,”“an illustrative embodiment,” etc., indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may or may not necessarily includethat particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. Further,when a particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to effect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described. Additionally, it should be appreciated that itemsincluded in a list in the form of “at least one of A, B, and C” can mean(A); (B); (C): (A and B); (A and C); (B and C); or (A, B, and C).Similarly, items listed in the form of “at least one of A, B, or C” canmean (A); (B); (C): (A and B); (A and C); (B and C); or (A, B, and C).

The disclosed embodiments may be implemented, in some cases, inhardware, firmware, software, or any combination thereof. The disclosedembodiments may also be implemented as instructions carried by or storedon one or more transitory or non-transitory machine-readable (e.g.,computer-readable) storage media, which may be read and executed by oneor more processors. A machine-readable storage medium may be embodied asany storage device, mechanism, or other physical structure for storingor transmitting information in a form readable by a machine (e.g., avolatile or non-volatile memory, a media disc, or other media device).

In the drawings, some structural or method features may be shown inspecific arrangements and/or orderings. However, it should beappreciated that such specific arrangements and/or orderings may not berequired. Rather, in some embodiments, such features may be arranged ina different manner and/or order than shown in the illustrative figures.Additionally, the inclusion of a structural or method feature in aparticular figure is not meant to imply that such feature is required inall embodiments and, in some embodiments, may not be included or may becombined with other features.

Referring now to FIG. 1, an Ethernet port logic 100 is configured as anetwork controller or other network port logic to communicate over oneor more physical communication lanes 102, which may be embodied astwinaxial copper cabling. In the illustrative embodiment, the Ethernetport logic 100 is configured to perform an autonegotiation process witha remote link partner. During autonegotiation, the Ethernet port logic100 informs the link partner about the various technologies forcommunication over copper cabling that are supported (e.g., 1-gigabit or10-gigabit single-lane communication). If at least one supportedcommunications technology is also supported by the remote link partner,the Ethernet port logic 100 may bring up the communication link usingthe fastest common single-lane communication technology. Additionally,the Ethernet port logic 100 may provide re-negotiation and activation ofslower communications technologies that are supported by both partnerswhen desirable, e.g., during low-power operation or when communicatingover a lower-quality physical medium. Thus, the autonegotiation processperformed by the Ethernet port logic 100 may allow configuration of thecommunication link without requiring synchronized manual configurationor out-of-band communication and synchronization. Also, the Ethernetport logic 100 may perform autonegotiation without externalconfiguration or other intervention by external firmware or software,which may allow link configuration when a computing device's mainprocessor is powered down, such as in a connected standby powermanagement state. The Ethernet port logic 100 may also allowautonegotiation of slower single-lane link speeds when one of the linkpartners also supports a future, higher-speed single-lane communicationtechnology (e.g., 25-gigabit single-lane communications over coppercabling).

The illustrative Ethernet port logic 100 includes an autonegotiationmodule 104, a physical medium dependent (PMD) sublayer/physical mediumattachment (PMA) sublayer 106, a forward error correction (FEC) sublayer108, a physical coding sublayer (PCS) module 110, and a reconciliationsublayer/media access control sublayer (MAC) module 112. Additionally,in some embodiments, one or more of the illustrative components may beincorporated in, or otherwise form a portion of, another component. Forexample, part or all of the autonegotiation module 104, the PMD/PMA 106,and/or the FEC 108 may be incorporated in the PCS 110.

The communication lanes 102 may be embodied as any one or more computercommunication links. For example, each communication lane 102 may beembodied as a twinaxial copper cable or as an electrical backplaneconnection. In some embodiments, each communication lane 102 may becapable of full-duplex operation. For example, each communication lane102 may include two twinaxial pairs of electrical conductors, one pairfor transmitting data and the other pair for receiving data.Illustratively, the communication lanes 102 may include a singlecommunication lane 102 capable of operating at 10 Gb/s or 1 Gb/s.Although described as operating at a data rate such as 10 Gb/s, itshould be understood that in some embodiments each of the communicationslanes 102 may operate at a slightly higher signaling rate such as 12.5Gb/s or 10.3125 Gb/s, to allow for additional data for line encoding,error correction, and other additional data.

The autonegotiation module 104 is configured to auto-negotiate linetransmission speed, mode of operation, and other communicationparameters with a link partner when the communication lane 102 isbrought up. Additionally, the autonegotiation module 104 is configuredto exchange technology abilities information with the link partner. Thetechnology abilities information may identify one or more relativelyslower communications over copper cable operational modes (also known asphysical layer technologies or technology abilities). For example, thetechnology abilities information may identify 10-gigabit single-lanecommunication over copper cabling and/or 1-gigabit single-lanecommunication over copper cabling. The autonegotiation module 104 mayencode the technology abilities information in an autonegotiation pagesuch as a base page (also called a base link codeword) or in a nextpage. The autonegotiation module 104 is further configured to bring upthe communication lane 102 with the remote link partner using a commonoperational mode determined from the exchanged autonegotiation pages.Although illustrated in FIG. 1 as coupled between the PMD/PMA 106 andthe communication lanes 102, in other embodiments the autonegotiationmodule 104 may be included at different positions in the Ethernet portlogic 100. For example, in some embodiments the autonegotiation module104 may be coupled between the PMD/PMA 106 and the FEC 108.

The PMD/PMA 106 is configured to transmit and receive serial binary dataover the communication lanes 102. The PMD/PMA 106 may be embodied as,for example, a serializer/deserializer (SERDES) that converts serialdata to parallel data. The SERDES may convert the serial data using, forexample, a shift register.

The FEC 108 may be configured to apply a forward error correction code(FEC) to the data passed between the PMD/PMA 106 and the PCS 110. Inother words, the FEC 108 may encode data passed from the PCS 110 to thePMD/PMA 106 and decode data passed from the PMD/PMA 106 to the PCS 110.The forward error correction code (FEC) may improve the reliability ofdata transmission at higher line speeds. The FEC 108 may apply anyappropriate forward error correction code, such as a Reed-Solomon FECdescribed by clause 91 of the IEEE standard 802.3 (2012) or the FECdescribed by clause 74 of the IEEE standard 802.3 (2012). In someembodiments, the Ethernet port logic 100 may not include an FEC 108and/or the FEC 108 may be optional. For example, for 1000 BASE-KR, theEthernet port logic 100 does not include an FEC 108. For 10 GBASE-KR and40 GBASE-KR, the FEC 108 may be optional per the IEEE standard. For 100GBASE technologies, the remote link partner may be required to sendRS-FEC encoded data but the local receiver may determine if the use ofthe FEC 108 is necessary. In embodiments that do not include the FEC108, the PCS 110 may be coupled directly to the PMD/PMA 106.

The PCS 110 is configured to encode Ethernet frame data received fromthe MAC 112 into encoded data blocks that may be transmitted by thePMD/PMA 106, and to decode data received from the PMD/PMA 106 intodecoded Ethernet frame data that may be processed by the MAC 112. ThePCS 110 may encode and distribute the data blocks over one or morelogical PCS lanes. The PCS 110 may encode data for transmission over thecommunication lanes 102, for example, to improve communicationefficiency. Encoding the data may add timing or synchronization symbols,align the data, add state transitions to the encoded data to improveclock recovery, adjust the DC balance of the data signal, or otherwiseprepare the encoded data for serial transmission. The PCS 110 may becapable of encoding or decoding the data using a 64 b/66 b line code inwhich 64-bit blocks of data are encoded into 66-bit blocks of encodeddata, and vice versa. In some embodiments, the PCS 110 may be capable ofencoding or decoding the data using an 8 b/10 b line code in which 8-bitblocks of data are encoded into 10-bit blocks of encoded data, and viceversa.

The MAC 112 is configured to transmit Ethernet frame data to the PCS 110to be encoded and transmitted, and to receive data from the PCS 110 toproduce Ethernet frame data. The MAC 112 may perform Ethernet framedetection and validation, packet reception and transmission, cyclicredundancy check (CRC) validation, CRC computation, and other mediaaccess control sublayer operations.

Referring now to FIG. 2, in an illustrative embodiment, a computingdevice 200 may include the Ethernet port logic 100. The computing device200 may be embodied as any type of computation or computer devicecapable of performing the functions described herein, including, withoutlimitation, a computer, a smartphone, a tablet computer, a laptopcomputer, a notebook computer, a mobile computing device, a wearablecomputing device, a multiprocessor system, a server, a rack-mountedserver, a blade server, a network switch, a network appliance, a webappliance, a distributed computing system, a processor-based system,and/or a consumer electronic device. As shown in FIG. 1, the computingdevice 200 illustratively includes a processor 220, an input/outputsubsystem 222, a memory 224, a data storage device 226, and a networkinterface circuit or card (NIC) 228. Of course, the computing device 200may include other or additional components, such as those commonly foundin a computer (e.g., various input/output devices), in otherembodiments. Additionally, in some embodiments, one or more of theillustrative components may be incorporated in, or otherwise form aportion of, another component. For example, the memory 224, or portionsthereof, may be incorporated in the processor 220 in some embodiments.

The processor 220 may be embodied as any type of processor capable ofperforming the functions described herein. For example, the processor220 may be embodied as a single or multi-core processor(s), digitalsignal processor, microcontroller, or other processor orprocessing/controlling circuit. Similarly, the memory 224 may beembodied as any type of volatile or non-volatile memory or data storagecapable of performing the functions described herein. In operation, thememory 224 may store various data and software used during operation ofthe computing device 200 such as operating systems, applications,programs, libraries, and drivers. The memory 224 is communicativelycoupled to the processor 220 via the I/O subsystem 222, which may beembodied as circuitry and/or components to facilitate input/outputoperations with the processor 220, the memory 224, and other componentsof the computing device 200. For example, the I/O subsystem 222 may beembodied as, or otherwise include, memory controller hubs, input/outputcontrol hubs, firmware devices, communication links (i.e.,point-to-point links, bus links, wires, cables, light guides, printedcircuit board traces, etc.) and/or other components and subsystems tofacilitate the input/output operations. In some embodiments, the I/Osubsystem 222 may form a portion of a system-on-a-chip (SoC) and beincorporated, along with the processor 220, the memory 224, and othercomponents of the computing device 200, on a single integrated circuitchip. The data storage device 226 may be embodied as any type of deviceor devices configured for short-term or long-term storage of data suchas, for example, memory devices and circuits, memory cards, hard diskdrives, solid-state drives, or other data storage devices.

The NIC 228 may connect the computing device 200 to one or morecomputing devices, network devices, switches, remote hosts, or otherdevices. The NIC 228 may be embodied as one or more add-in-boards,daughtercards, controller chips, chipsets, circuits, or other devicesthat may be used by the computing device 200 for network communicationswith remote devices. For example, the NIC 228 may be embodied as anexpansion card coupled to the I/O subsystem 222 over an expansion bussuch as PCI Express. In the illustrative embodiment, the NIC 228includes a single Ethernet port logic 100 to connect to the remotedevices. Of course, in other embodiments the computing device 200 mayinclude additional or fewer Ethernet port logics 100 to support adifferent number of communication lanes 102.

In some embodiments, the computing device 200 may also include one ormore peripheral devices 230. The peripheral devices 230 may include anynumber of additional input/output devices, interface devices, and/orother peripheral devices. For example, in some embodiments, theperipheral devices 230 may include a display, touch screen, graphicscircuitry, keyboard, mouse, speaker system, network interface, and/orother input/output devices, interface devices, and/or peripheraldevices.

Referring now to FIG. 3, in use, the Ethernet port logic 100 may executea method 300 for link technology autonegotiation. The method 300 beginsin block 302, in which the Ethernet port logic 100 starts theautonegotiation process. The autonegotiation process may be started whenthe Ethernet port logic 100 is powered on or when the physicalcommunication lane 102 is connected. The autonegotiation process mayalso be started when the communication link is restarted or otherwiserenegotiated. For example, the link may be broken and theautonegotiation process may be restarted when lower communication speedsare desired, such as when the physical medium quality is poor. Theautonegotiation process may be restarted automatically or manually(e.g., in response to an administrator command)

In block 304, the Ethernet port logic 100 transmits a base page over thephysical communication lane 102 to the remote link partner. The basepage (also known as a base link codeword) may be embodied as any blockof data initially transmitted during the autonegotiation process. Forexample, the base page may be embodied as a 48-bit data page encodedusing a differential Manchester encoding (DME). The base page may be thesame or similar to the base page described by the IEEE standard 802.3,clause 73.6 (2012). The Ethernet port logic 100 may continually transmitthe base page until its receipt has been acknowledged by the remote linkpartner, as described below. In some embodiments, information describingsingle-lane communication over copper cable technology abilities may beincluded in the base page.

Referring now to FIG. 4, the diagram 400 illustrates one potentialembodiment of a base page 402. As shown, the base page 402 includes 48bits organized into several bits and groups of bits called fields. Inparticular, the base page 402 includes a selector field S, an echoednonce field E, a capability field C, a remote fault bit RF, an ACK bit,a next page bit NP, a transmitted nonce field T, a technology abilityfield A, and a forward error correction capability field F.

Referring back to FIG. 3, in some embodiments, in block 306 the Ethernetport logic 100 may set the next page flag NP of the base page. The nextpage flag indicates that the Ethernet port logic 100 will send more datain one or more additional data pages (called “next pages”) after thebase page. The Ethernet port logic 100 may set the next page flag if,for example, the information describing single-lane communication overcopper cable technology abilities is not included in the base page andwill be included in a next page.

In some embodiments, in block 308, the Ethernet port logic 100 mayadvertise one or more single-lane communication over copper cableoperational modes to the remote link partner in the base page. Forexample, the Ethernet port logic 100 may encode that information in theability field A of the base page, for example by enabling specificcombinations of features. For example, to advertise 10-gigabitcommunication over copper cable, the Ethernet port logic 100 may setbits for 40-gigabit multi-lane communication over copper cable (40GBASE-CR4, bit A[4]) and 10-gigabit communication over backplane (10GBASE-KR, bit A[2]). As another example, to advertise 1-gigabitcommunication over copper cable, the Ethernet port logic 100 may setbits for 40-gigabit multi-lane communication over copper cable (40GBASE-CR4, bit A[4]) and 1-gigabit communication over backplane (1000BASE-KX, bit A[0]). Those combinations of bits may typically beprohibited by networking specifications or otherwise mutually exclusivebecause they operate on different physical media (i.e., copper cablesand backplane). As another example, the Ethernet port logic 100 mayadvertise one or more communication over copper cable operational modesby advertising only backplane technologies over a copper cable medium.For example, to advertise 10-gigabit communication over copper cable,the Ethernet port logic 100 may set a bit for 10-gigabit communicationover backplane (10 GBASE-KR, bit A[2]), and to advertise 1-gigabitcommunication over copper cable, the Ethernet port logic 100 may set abit for 1-gigabit communication over backplane (1000 BASE-KX, bit A[0]).

In block 310, the Ethernet port logic 100 receives a base page from theremote link partner. The base page received from the remote link partnermay be formatted similarly to the base page transmitted to the remotelink partner. Thus, the base page received from the remote link partnermay indicate that the remote link partner will transmit a next page, ormay advertise one or more single-lane communication over copper cableoperational modes. The Ethernet port logic 100 may ensure that it hasreceived an identical base page several times (e.g., at least threetimes) prior to proceeding. Additionally, although illustrated asoccurring sequentially after transmitting the base page, it should beunderstood that the Ethernet port logic 100 may transmit and receiveautonegotiation pages simultaneously.

In block 312, the Ethernet port logic 100 acknowledges receipt of thebase page to the remote link partner. The Ethernet port logic 100 may,for example, continue transmitting the base page with the ACK bit set,with the echoed nonce field E set to a nonce received from the linkpartner, or with any other indication of acknowledgement. The Ethernetport logic 100 may also verify that the remote link partner hassimilarly acknowledged receipt of the base page.

In block 314, the Ethernet port logic 100 determines whether to transmita next page to the remote link partner. The Ethernet port logic 100 maytransmit a next page, for example, to transmit information onsingle-lane communication over copper cable technology abilities to theremote link partner. The Ethernet port logic 100 may also transmit anull, zeroed, or otherwise empty next page if the remote link partnerhas indicated that it will transmit a next page (for example by settingthe NP bit of the base page), even if the Ethernet port logic 100 has nonext page information of its own. If the Ethernet port logic 100determines not to transmit a next page, for example if all pages havebeen transmitted, the method 300 branches ahead to block 326. If theEthernet port logic 100 determines to transmit a next page, the method300 advances to block 316.

In block 316, the Ethernet port logic 100 transmits a next page to theremote link partner. The next page may be embodied as a block of datatransmitted during the autonegotiation process similar to a base page.For example, the next page may be embodied as a 48-bit data page encodedusing a differential Manchester encoding (DME). The next page may be thesame or similar to the next page described by the IEEE standard 802.3,clause 73.7.7 (2012). The Ethernet port logic 100 may continuallytransmit the next page until its receipt has been acknowledged by theremote link partner, as described below. In some embodiments,information describing communication over copper cable technologyabilities may be included in the next page.

Referring now to FIG. 4, the diagram 400 illustrates two potentialembodiments of next pages 404, 406. As shown, each of the next pages404, 406 includes 48 bits organized into several bits and groups of bitscalled fields (not to scale). The next page 404 is a message next page,and includes both a message code field M and an unformatted code fieldU. In particular, the message next page includes the message code fieldM, a toggle bit T, an acknowledge 2 bit ACK 2, a message page bit MP(always set for message next pages 404), an acknowledge bit ACK, a nextpage bit NP, and the unformatted code field U. The next page 406 is anunformatted next page, and includes the unformatted code field U, thetoggle bit T, the acknowledge 2 bit ACK 2, the message page bit MP(always unset for unformatted next pages 406), the acknowledge bit ACK,and the next page bit NP, but does not include the message code field M.

Referring back to FIG. 3, in some embodiments in block 318 the Ethernetport logic 100 may transmit a message next page. In those embodiments,the message code field M may be set to a unique identifier, for exampleto a binary representation of the value 32, or other identifier. Theunique identifier may be reserved or otherwise not specified by IEEEstandard 802.3 (2012). In those embodiments, one or more bits of theunformatted code field U may be set to indicate single-lanecommunication over copper cable technology abilities. For example, bitU[0] may be set to indicate 1-gigabit communication over copper cabletechnology ability, and bit U[1] may be set to indicate 10-gigabitcommunication over copper cable technology ability.

In some embodiments, in block 320, the Ethernet port logic 100 maytransmit an unformatted next page. For example, in some embodiments theEthernet port logic 100 may first transmit a message next page thatincludes the organizationally unique identifier (OUI) tagged messagecode and an organizationally unique identifier (OUI) associated with avendor or other organization related to the Ethernet port logic 100. Inthose embodiments, after transmitting the OUI tagged message code page,the Ethernet port logic 100 may next transmit an unformatted next pageincluding a user-defined code in the unformatted code field U. In thoseembodiments, similar to a message next page described in connection withblock 318, one or more bits of the unformatted code field U may be setto indicate single-lane communication over copper cable technologyabilities. For example, bit U[0] may be set to indicate 1-gigabitcommunication over copper cable technology ability, and bit U[1] may beset to indicate 10-gigabit communication over copper cable technologyability.

In block 322, the Ethernet port logic 100 receives a next page from theremote link partner. The next page received from the remote link partnermay be formatted similarly to the next page transmitted to the remotelink partner. Thus, the next page received from the remote link partnermay indicate one or more single-lane communication over copper cabletechnology abilities. The next page received from the remote linkpartner may also indicate whether additional next pages remain to betransmitted. The Ethernet port logic 100 may ensure that it has receivedan identical next page several times (e.g., at least three times) priorto proceeding. Additionally, although illustrated as occurringsequentially after transmitting the next page, it should be understoodthat the Ethernet port logic 100 may transmit and receiveautonegotiation next pages simultaneously.

In block 324, the Ethernet port logic 100 acknowledges receipt of thenext page to the remote link partner. The Ethernet port logic 100 may,for example, continue transmitting the next page with the ACK bit set,with the echoed nonce field E set to a nonce received from the linkpartner, or with any other indication of acknowledgement. The Ethernetport logic 100 may set the ACK 2 bit if the Ethernet port logic 100 isable to act on the information or perform the task described in the nextpage. The Ethernet port logic 100 may also verify that the remote linkpartner has similarly acknowledged receipt of the next page. Afteracknowledging receipt of the next page, the method 300 loops back toblock 314 to determine whether additional next pages should beexchanged.

Referring back to block 314, if no additional next pages remain, themethod 300 branches to block 326. In block 326, the Ethernet port logic100 determines the operational mode to use for the physicalcommunication lane 102 based on common technological abilities exchangedwith the remote link partner. The Ethernet port logic 100 may use anyrules, policies, or conflict resolution algorithm to determine the lanetechnology. For example, the Ethernet port logic 100 may select the“highest common denominator” technology shared by the Ethernet portlogic 100 and the remote link partner. In other words, the Ethernet portlogic 100 may find all common technologies with the remote link partnerand select the technology with the highest predefined priority. In thatexample, the Ethernet port logic 100 may select a communication overcopper cable technology at 1 Gb/s or 10 Gb/s only if fastercommunication over copper cable technologies (e.g., 100 GBASE-CR10 or 40GBASE-CR4) are not available. As another example, the Ethernet portlogic 100 may always select a shared communication over copper cabletechnology at 1 Gb/s or 10 Gb/s. In that example, the Ethernet portlogic 100 may select 1 Gb/s or 10 Gb/s single-lane communication overcopper cable even if the Ethernet port logic 100 and the remote linkpartner are both capable of faster multi-lane communication over coppercable (e.g., 100 GBASE-CR10 or 40 GBASE-CR4). In particular, theEthernet port logic 100 and the remote link partner may both beconfigured to select communication over copper cable technologiesadvertised in a next page instead of multi-lane communicationtechnologies advertised in the base page, overriding the autonegotiationbehavior specified by clause 73 of the IEEE standard 802.3 (2012).

In block 328, the Ethernet port logic 100 brings up the communicationlink with the remote link partner using the operational mode determinedabove in connection with block 326. If bringing up 1-gigabitcommunication over copper cable, the Ethernet port logic 100 may operateas described for 1-gigabit communication over backplane (1000 BASE-KX)in the IEEE standard 802.3, at clause 70 (2012). If bringing up10-gigabit communication over copper cable, the Ethernet port logic 100may operate as described for 10-gigabit communication over backplane (10GBASE-KR) in the IEEE standard 802.3, at clause 72 (2012). The Ethernetport logic 100 may apply data encoding as appropriate for the selectedoperational mode. For example, an 8 b/10 b encoding (described by clause36 of the IEEE standard 802.3) may be used for 1 Gb/s communications anda 64 b/66 b encoding (described by clause 49 of the IEEE standard 802.3)may be used for 10 Gb/s communications. The Ethernet port logic 100 mayalso apply a link training procedure if supported by the selectedoperational mode. For example, the PMD control function (described byclause 72.6.10 of the IEEE standard 802.3) may be applied for 10 Gb/scommunications, but not for 1 Gb/s communications. If the Ethernet portlogic 100 fails to bring up the communication link, the Ethernet portlogic 100 may restart the autonegotiation process of the method 300, andthe Ethernet port logic 100 may attempt to use a slower operational modewhen renegotiating the communication link. For example, if bringing upthe communication link fails for 40-gigabit multi-lane communicationsover copper cable (40 GBASE-CR4), the Ethernet port logic 100 mayattempt to renegotiate the communication link using 10-gigabit or1-gigabit communications over copper cable.

In block 330, the Ethernet port logic 100 ends the autonegotiationprocess. After completing the autonegotiation process, the Ethernet portlogic 100 transmits and receives data as normal, using theautonegotiated operational mode. The Ethernet port logic 100 may notperform any autonegotiation or transmit autonegotiation pages while thecommunication link is active with the remote link partner. As describedabove, the Ethernet port logic 100 may restart the autonegotiationmethod 300 if the communication link is broken or disconnected, if theEthernet port logic 100 is power-cycled, or if a manual renegotiationhas been triggered.

EXAMPLES

Illustrative examples of the technologies disclosed herein are providedbelow. An embodiment of the technologies may include any one or more,and any combination of, the examples described below.

Example 1 includes a network interface circuit for link technologyautonegotiation, the network interface circuit comprising a network portlogic comprising an autonegotiation logic, wherein the autonegotiationlogic is to transmit a first autonegotiation page to a remote linkpartner, wherein the first autonegotiation page is indicative of a firstoperational mode, wherein the first operational mode includessingle-lane communication over copper cable; receive a secondautonegotiation page from the remote link partner, wherein the secondautonegotiation page is indicative of the first operational mode; andactivate a communication link with the remote link partner using thefirst operational mode in response to transmission of the firstautonegotiation page and reception of the second autonegotiation page.

Example 2 includes the subject matter of Example 1, and wherein theautonegotiation logic is further to determine whether the secondautonegotiation page is indicative of the first operational mode; and toactivate the communication link comprises to activate the communicationlink in response to a determination that the second autonegotiation pageis indicative of the first operational mode.

Example 3 includes the subject matter of any of Examples 1 and 2, andwherein to transmit the first autonegotiation page comprises to transmita 48-bit data page using a differential Manchester encoding via thecommunication link with the remote link partner; and to receive thesecond autonegotiation page comprises to receive a 48-bit data pageusing the differential Manchester encoding via the communication linkwith the remote link partner.

Example 4 includes the subject matter of any of Examples 1-3, andwherein the first operational mode comprises a 10-gigabit communicationover backplane technology ability using a copper cable medium.

Example 5 includes the subject matter of any of Examples 1-4, andwherein the first operational mode comprises a 1-gigabit communicationover backplane technology ability using a copper cable medium.

Example 6 includes the subject matter of any of Examples 1-5, andwherein to transmit the first autonegotiation page comprises to transmita first next page that includes a technology ability bit, wherein thetechnology ability bit is indicative of the first operational mode; andto receive the second autonegotiation page comprises to receive a secondnext page including a technology ability bit, wherein the technologyability bit is indicative of the first operational mode.

Example 7 includes the subject matter of any of Examples 1-6, andwherein the first next page further comprises a message code fieldindicative of a first unique identifier; and the second next pagefurther comprises a message code field indicative of the first uniqueidentifier.

Example 8 includes the subject matter of any of Examples 1-7, andwherein the autonegotiation logic is further to transmit a thirdautonegotiation page to the remote link partner, wherein the thirdautonegotiation page comprises a message code field indicative of anorganizationally unique identifier tagged message code and anunformatted code indicative of an organizationally unique identifier;and receive a fourth autonegotiation page from the remote link partner,wherein the fourth autonegotiation page comprises a message code fieldindicative of the organizationally unique identifier tagged message codeand an unformatted code indicative of the organizationally uniqueidentifier.

Example 9 includes the subject matter of any of Examples 1-8, andwherein the autonegotiation logic is further to transmit a first basepage to the remote link partner, wherein the first base page isindicative of a second operational mode, wherein the second operationalmode includes multi-lane communication over copper cable; and receive asecond base page from the remote link partner, wherein the second basepage is indicative of the second operational mode.

Example 10 includes the subject matter of any of Examples 1-9, andwherein to transmit the first autonegotiation page comprises to transmita first base page that includes a technology ability field, wherein thetechnology ability field is indicative of the first operational mode;and to receive the second autonegotiation page comprises to receive asecond base page that includes a technology ability field, wherein thetechnology ability field is indicative of the first operational mode.

Example 11 includes the subject matter of any of Examples 1-10, andwherein the technology ability field of the first base page isindicative of a communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of thecommunication over backplane technology ability.

Example 12 includes the subject matter of any of Examples 1-11, andwherein the technology ability field of the first base page isindicative of a 10-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 10-gigabit communication over backplane technologyability.

Example 13 includes the subject matter of any of Examples 1-12, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

Example 14 includes the subject matter of any of Examples 1-13, andwherein the technology ability field of the first base page isindicative of a 1-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 1-gigabit communication over backplane technologyability.

Example 15 includes the subject matter of any of Examples 1-14, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

Example 16 includes a method for link technology autonegotiation, themethod comprising transmitting, by a network port logic, a firstautonegotiation page to a remote link partner, wherein the firstautonegotiation page is indicative of a first operational mode, whereinthe first operational mode includes single-lane communication overcopper cable; receiving, by the network port logic, a secondautonegotiation page from the remote link partner, wherein the secondautonegotiation page is indicative of the first operational mode; andactivating, by the network port logic, a communication link with theremote link partner using the first operational mode in response totransmitting the first autonegotiation page and receiving the secondautonegotiation page.

Example 17 includes the subject matter of Example 16, and furtherincluding determining, by the network port logic, whether the secondautonegotiation page is indicative of the first operational mode;wherein activating the communication link comprises activating thecommunication link in response to determining the second autonegotiationpage is indicative of the first operational mode.

Example 18 includes the subject matter of any of Examples 16 and 17, andwherein transmitting the first autonegotiation page comprisestransmitting a 48-bit data page using a differential Manchester encodingvia the communication link with the remote link partner; and receivingthe second autonegotiation page comprises receiving a 48-bit data pageusing the differential Manchester encoding via the communication linkwith the remote link partner.

Example 19 includes the subject matter of any of Examples 16-18, andwherein the first operational mode comprises a 10-gigabit communicationover backplane technology ability using a copper cable medium.

Example 20 includes the subject matter of any of Examples 16-19, andwherein the first operational mode comprises a 1-gigabit communicationover backplane technology ability using a copper cable medium.

Example 21 includes the subject matter of any of Examples 16-20, andwherein transmitting the first autonegotiation page comprisestransmitting a first next page including a technology ability bit,wherein the technology ability bit is indicative of the firstoperational mode; and receiving the second autonegotiation pagecomprises receiving a second next page including a technology abilitybit, wherein the technology ability bit is indicative of the firstoperational mode.

Example 22 includes the subject matter of any of Examples 16-21, andwherein the first next page further comprises a message code fieldindicative of a first unique identifier; and the second next pagefurther comprises a message code field indicative of the first uniqueidentifier.

Example 23 includes the subject matter of any of Examples 16-22, andfurther including transmitting, by the network port logic, a thirdautonegotiation page to the remote link partner, wherein the thirdautonegotiation page comprises a message code field indicative of anorganizationally unique identifier tagged message code and anunformatted code indicative of an organizationally unique identifier;and receiving, by the network port logic, a fourth autonegotiation pagefrom the remote link partner, wherein the fourth autonegotiation pagecomprises a message code field indicative of the organizationally uniqueidentifier tagged message code and an unformatted code indicative of theorganizationally unique identifier.

Example 24 includes the subject matter of any of Examples 16-23, andfurther including transmitting, by the network port logic, a first basepage to the remote link partner, wherein the first base page isindicative of a second operational mode, wherein the second operationalmode includes multi-lane communication over copper cable; and receiving,by the network port logic, a second base page from the remote linkpartner, wherein the second base page is indicative of the secondoperational mode.

Example 25 includes the subject matter of any of Examples 16-24, andwherein transmitting the first autonegotiation page comprisestransmitting a first base page including a technology ability field,wherein the technology ability field is indicative of the firstoperational mode; and receiving the second autonegotiation pagecomprises receiving a second base page including a technology abilityfield, wherein the technology ability field is indicative of the firstoperational mode.

Example 26 includes the subject matter of any of Examples 16-25, andwherein the technology ability field of the first base page isindicative of a communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of thecommunication over backplane technology ability.

Example 27 includes the subject matter of any of Examples 16-26, andwherein the technology ability field of the first base page isindicative of a 10-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 10-gigabit communication over backplane technologyability.

Example 28 includes the subject matter of any of Examples 16-27, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

Example 29 includes the subject matter of any of Examples 16-28, andwherein the technology ability field of the first base page isindicative of a 1-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 1-gigabit communication over backplane technologyability.

Example 30 includes the subject matter of any of Examples 16-29, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

Example 31 includes a computing device comprising a processor; and amemory having stored therein a plurality of instructions that whenexecuted by the processor cause the computing device to perform themethod of any of Examples 16-30.

Example 32 includes one or more machine readable storage mediacomprising a plurality of instructions stored thereon that in responseto being executed result in a computing device performing the method ofany of Examples 16-30.

Example 33 includes a computing device comprising means for performingthe method of any of Examples 16-30.

Example 34 includes a computing device for link technologyautonegotiation, the computing device comprising means for transmittinga first autonegotiation page to a remote link partner, wherein the firstautonegotiation page is indicative of a first operational mode, whereinthe first operational mode includes single-lane communication overcopper cable; means for receiving a second autonegotiation page from theremote link partner, wherein the second autonegotiation page isindicative of the first operational mode; and means for activating acommunication link with the remote link partner using the firstoperational mode in response to transmitting the first autonegotiationpage and receiving the second autonegotiation page.

Example 35 includes the subject matter of Example 34, and furtherincluding means for determining whether the second autonegotiation pageis indicative of the first operational mode; wherein the means foractivating the communication link comprises means for activating thecommunication link in response to determining the second autonegotiationpage is indicative of the first operational mode.

Example 36 includes the subject matter of any of Examples 34 and 35, andwherein the means for transmitting the first autonegotiation pagecomprises means for transmitting a 48-bit data page using a differentialManchester encoding via the communication link with the remote linkpartner; and the means for receiving the second autonegotiation pagecomprises means for receiving a 48-bit data page using the differentialManchester encoding via the communication link with the remote linkpartner.

Example 37 includes the subject matter of any of Examples 34-36, andwherein the first operational mode comprises a 10-gigabit communicationover backplane technology ability using a copper cable medium.

Example 38 includes the subject matter of any of Examples 34-37, andwherein the first operational mode comprises a 1-gigabit communicationover backplane technology ability using a copper cable medium.

Example 39 includes the subject matter of any of Examples 34-38, andwherein the means for transmitting the first autonegotiation pagecomprises means for transmitting a first next page including atechnology ability bit, wherein the technology ability bit is indicativeof the first operational mode; and the means for receiving the secondautonegotiation page comprises means for receiving a second next pageincluding a technology ability bit, wherein the technology ability bitis indicative of the first operational mode.

Example 40 includes the subject matter of any of Examples 34-39, andwherein the first next page further comprises a message code fieldindicative of a first unique identifier; and the second next pagefurther comprises a message code field indicative of the first uniqueidentifier.

Example 41 includes the subject matter of any of Examples 34-40, andfurther including means for transmitting a third autonegotiation page tothe remote link partner, wherein the third autonegotiation pagecomprises a message code field indicative of an organizationally uniqueidentifier tagged message code and an unformatted code indicative of anorganizationally unique identifier; and means for receiving a fourthautonegotiation page from the remote link partner, wherein the fourthautonegotiation page comprises a message code field indicative of theorganizationally unique identifier tagged message code and anunformatted code indicative of the organizationally unique identifier.

Example 42 includes the subject matter of any of Examples 34-41, andfurther including means for transmitting a first base page to the remotelink partner, wherein the first base page is indicative of a secondoperational mode, wherein the second operational mode includesmulti-lane communication over copper cable; and means for receiving asecond base page from the remote link partner, wherein the second basepage is indicative of the second operational mode.

Example 43 includes the subject matter of any of Examples 34-42, andwherein the means for transmitting the first autonegotiation pagecomprises means for transmitting a first base page including atechnology ability field, wherein the technology ability field isindicative of the first operational mode; and the means for receivingthe second autonegotiation page comprises means for receiving a secondbase page including a technology ability field, wherein the technologyability field is indicative of the first operational mode.

Example 44 includes the subject matter of any of Examples 34-43, andwherein the technology ability field of the first base page isindicative of a communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of thecommunication over backplane technology ability.

Example 45 includes the subject matter of any of Examples 34-44, andwherein the technology ability field of the first base page isindicative of a 10-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 10-gigabit communication over backplane technologyability.

Example 46 includes the subject matter of any of Examples 34-45, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

Example 47 includes the subject matter of any of Examples 34-46, andwherein the technology ability field of the first base page isindicative of a 1-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 1-gigabit communication over backplane technologyability.

Example 48 includes the subject matter of any of Examples 34-47, andwherein the technology ability field of the first base page is furtherindicative of a 40-gigabit multi-lane communication over copper cabletechnology ability; and the technology ability field of the second basepage is further indicative of the 40-gigabit multi-lane communicationover copper cable technology ability.

1. A network interface circuit for link technology autonegotiation, thenetwork interface circuit comprising: a network port logic comprising anautonegotiation logic, wherein the autonegotiation logic is to: transmita first autonegotiation page to a remote link partner, wherein the firstautonegotiation page is indicative of a first operational mode, whereinthe first operational mode includes single-lane communication overcopper cable; receive a second autonegotiation page from the remote linkpartner, wherein the second autonegotiation page is indicative of thefirst operational mode; and activate a communication link with theremote link partner using the first operational mode in response toreception of the second autonegotiation page.
 2. The network interfacecircuit of claim 1, wherein the first operational mode comprises a10-gigabit communication over backplane technology ability using acopper cable medium.
 3. The network interface circuit of claim 1,wherein the first operational mode comprises a 1-gigabit communicationover backplane technology ability using a copper cable medium.
 4. Thenetwork interface circuit of claim 1, wherein: to transmit the firstautonegotiation page comprises to transmit a first next page thatincludes a technology ability bit, wherein the technology ability bit isindicative of the first operational mode; and to receive the secondautonegotiation page comprises to receive a second next page including atechnology ability bit, wherein the technology ability bit is indicativeof the first operational mode.
 5. The network interface circuit of claim4, wherein the autonegotiation logic is further to: transmit a firstbase page to the remote link partner, wherein the first base page isindicative of a second operational mode, wherein the second operationalmode includes multi-lane communication over copper cable; and receive asecond base page from the remote link partner, wherein the second basepage is indicative of the second operational mode.
 6. The networkinterface circuit of claim 1, wherein: to transmit the firstautonegotiation page comprises to transmit a first base page thatincludes a technology ability field, wherein the technology abilityfield is indicative of the first operational mode; and to receive thesecond autonegotiation page comprises to receive a second base page thatincludes a technology ability field, wherein the technology abilityfield is indicative of the first operational mode.
 7. The networkinterface circuit of claim 6, wherein: the technology ability field ofthe first base page is indicative of a communication over backplanetechnology ability; and the technology ability field of the second basepage is indicative of the communication over backplane technologyability.
 8. The network interface circuit of claim 7, wherein: thetechnology ability field of the first base page is indicative of a10-gigabit communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of the10-gigabit communication over backplane technology ability.
 9. Thenetwork interface circuit of claim 8, wherein: the technology abilityfield of the first base page is further indicative of a 40-gigabitmulti-lane communication over copper cable technology ability; and thetechnology ability field of the second base page is further indicativeof the 40-gigabit multi-lane communication over copper cable technologyability.
 10. The network interface circuit of claim 7, wherein: thetechnology ability field of the first base page is indicative of a1-gigabit communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of the1-gigabit communication over backplane technology ability.
 11. Thenetwork interface circuit of claim 10, wherein: the technology abilityfield of the first base page is further indicative of a 40-gigabitmulti-lane communication over copper cable technology ability; and thetechnology ability field of the second base page is further indicativeof the 40-gigabit multi-lane communication over copper cable technologyability.
 12. A method for link technology autonegotiation, the methodcomprising: transmitting, by a network port logic, a firstautonegotiation page to a remote link partner, wherein the firstautonegotiation page is indicative of a first operational mode, whereinthe first operational mode includes single-lane communication overcopper cable; receiving, by the network port logic, a secondautonegotiation page from the remote link partner, wherein the secondautonegotiation page is indicative of the first operational mode; andactivating, by the network port logic, a communication link with theremote link partner using the first operational mode in response toreceiving the second autonegotiation page.
 13. The method of claim 12,wherein: transmitting the first autonegotiation page comprisestransmitting a first next page including a technology ability bit,wherein the technology ability bit is indicative of the firstoperational mode; and receiving the second autonegotiation pagecomprises receiving a second next page including a technology abilitybit, wherein the technology ability bit is indicative of the firstoperational mode.
 14. The method of claim 13, further comprising:transmitting, by the network port logic, a first base page to the remotelink partner, wherein the first base page is indicative of a secondoperational mode, wherein the second operational mode includesmulti-lane communication over copper cable; and receiving, by thenetwork port logic, a second base page from the remote link partner,wherein the second base page is indicative of the second operationalmode.
 15. The method of claim 12, wherein: transmitting the firstautonegotiation page comprises transmitting a first base page includinga technology ability field, wherein the technology ability field isindicative of the first operational mode; and receiving the secondautonegotiation page comprises receiving a second base page including atechnology ability field, wherein the technology ability field isindicative of the first operational mode.
 16. The method of claim 15,wherein: the technology ability field of the first base page isindicative of a communication over backplane technology ability; and thetechnology ability field of the second base page is indicative of thecommunication over backplane technology ability.
 17. The method of claim16, wherein: the technology ability field of the first base page isindicative of a 10-gigabit communication over backplane technologyability; and the technology ability field of the second base page isindicative of the 10-gigabit communication over backplane technologyability.
 18. The method of claim 16, wherein: the technology abilityfield of the first base page is indicative of a 1-gigabit communicationover backplane technology ability; and the technology ability field ofthe second base page is indicative of the 1-gigabit communication overbackplane technology ability.
 19. One or more computer-readable storagemedia comprising a plurality of instructions that in response to beingexecuted cause a computing device to: transmit a first autonegotiationpage to a remote link partner, wherein the first autonegotiation page isindicative of a first operational mode, wherein the first operationalmode includes single-lane communication over copper cable; receive asecond autonegotiation page from the remote link partner, wherein thesecond autonegotiation page is indicative of the first operational mode;and activate a communication link with the remote link partner using thefirst operational mode in response to transmitting the firstautonegotiation page and receiving the second autonegotiation page. 20.The one or more computer-readable storage media of claim 19, wherein: totransmit the first autonegotiation page comprises to transmit a firstnext page including a technology ability bit, wherein the technologyability bit is indicative of the first operational mode; and to receivethe second autonegotiation page comprises to receive a second next pageincluding a technology ability bit, wherein the technology ability bitis indicative of the first operational mode.
 21. The one or morecomputer-readable storage media of claim 20, further comprising aplurality of instructions that in response to being executed cause thecomputing device to: transmit a first base page to the remote linkpartner, wherein the first base page is indicative of a secondoperational mode, wherein the second operational mode includesmulti-lane communication over copper cable; and receive a second basepage from the remote link partner, wherein the second base page isindicative of the second operational mode.
 22. The one or morecomputer-readable storage media of claim 19, wherein: to transmit thefirst autonegotiation page comprises to transmit a first base pageincluding a technology ability field, wherein the technology abilityfield is indicative of the first operational mode; and to receive thesecond autonegotiation page comprises to receive a second base pageincluding a technology ability field, wherein the technology abilityfield is indicative of the first operational mode.
 23. The one or morecomputer-readable storage media of claim 22, wherein: the technologyability field of the first base page is indicative of a communicationover backplane technology ability; and the technology ability field ofthe second base page is indicative of the communication over backplanetechnology ability.
 24. The one or more computer-readable storage mediaof claim 23, wherein: the technology ability field of the first basepage is indicative of a 10-gigabit communication over backplanetechnology ability; and the technology ability field of the second basepage is indicative of the 10-gigabit communication over backplanetechnology ability.
 25. The one or more computer-readable storage mediaof claim 23, wherein: the technology ability field of the first basepage is indicative of a 1-gigabit communication over backplanetechnology ability; and the technology ability field of the second basepage is indicative of the 1-gigabit communication over backplanetechnology ability.